Pedicle screw

Abstract

The present invention includes a pedicle screw made with a bone fastener and a rod coupling head, the rod coupling head comprising an upper rod coupling: the lower rod coupling having a lateral rod opening adapted to receive a permanent rod; an angled bore extends into the lateral rod opening; and a permanent rod fastener in the angled bore to engage a permanent rod in the lateral rod opening; and a upper rod coupling having an upper rod opening adapted to receive a temporary rod, wherein the upper rod opening is formed to receive a temporary rod fastener; wherein the upper rod coupling is detachable from the lower rod coupling at a transition and a temporary rod is temporarily affixed into the upper rod opening during a bone realignment and a permanent rod is positioned in the lateral rod opening and engaged by the permanent rod fastener upon final bone alignment.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application Ser. No. 61 / 025,760, filed Feb. 2, 2008, and to U.S. Provisional Application Ser. No. 61 / 080,150 filed Jul. 11, 2008, the contents of both of which is incorporated by reference herein in its entirety.TECHNICAL FIELD OF THE INVENTION[0002]The present invention relates in general to the field of bone fixation, and more particularly, to a novel pedicle screw for use in the correction of mild to severe spinal deformities.STATEMENT OF FEDERALLY FUNDED RESEARCH[0003]NoneBACKGROUND OF THE INVENTION[0004]Without limiting the scope of the invention, its background is described in connection with pedicle screws.[0005]In rigid severe spine deformity with coronal or sagittal decompensation, translation of the spinal column is necessary for restoration of trunk balance as well as deformity correction. However, the conventional correction methods, such as posterior correction only or ante...

AI Technical Summary

Benefits of technology

[0012]The present invention solves various problems of current pedicle screw and spinal fixation systems. The present invention allows the surgeon to stabilize the spine, effectively derotate the spine, safely translate the spine and when required easily derotate and translate the spine to treat spinal deformities.

[0013]The present inventors recognized there and other disadvantages of the current implant strategies used during Posterior Vertebral Column Resection (PVCR) by designing a new pedicle screw posterior instrumentation system. The present invention includes screws, methods, kits and systems that provide a safer, easier and better correction, as well as shorter operation time method for the PVCR of the severe spinal deformity. The present invention takes advantage of the top-loading and side-loading current designs as well as a universal connecting link to provide three-dimensional correction. These components provide: 1) continued stabilization of the spine during bony resection as well as correction; 2) allow for controlled correction of the spine using both rods; and 3) provide the ability to place the permanent rods while the long provisional rod is in places so instability is not created.

[0014]The present invention includes: 1) a pedicle screw with a screw head that can receive two rods. The bone screw head includes two rod-receivers. One receiver member is basic “U” shape (top-loading component) that extends from the top of the screw head to receive a temporary rod. Another receiver member has a basic “C” shape (side-loading component) that is inferior to the first receiver. The second receiver receives a final rod. There is also a breakaway mechanism between the first and second apertures so that the first aperture can be removed while the final rod is fixed; 2) rod-link reducer has a basic “H” shape that rigidly links and locks the temporary rods, which allows attachment to the rod at any orientation in the coronal, sagittal, and transverse planes so as to make compression, distraction, derotation and cantilever method; 3) reduction handle connects with the rod-link reducer; and 4) 5.5, mm diameter rod. For the PVCR of severe spinal deformity, this instrumentation system would provide: 1) better maintenance of spinal stability throughout the surgical procedure to reduce risk of the spinal cord injuries; 2) more reliable reconstruction of the vertebral column; 3) better and easier correction of the deformity; and 4) shorter operative time.

Problems solved by technology

However, the conventional correction methods, such as posterior correction only or anterior release and posterior instrumentation, are usually unsatisfactory.

However, the anterior-posterior vertebral column resection (VCR) has disadvantages such as long operative time, potential significant blood loss, and risk of intraoperative neurologic impairment due to the spinal column segment instability during the resection and the correction procedure.

However, these technique have a number of disadvantages: 1) the risk of intraoperative mishaps due to the instability resulting from exchanging the temporary rods may produce spinal cord injury; 2) limitation in deformity correction secondary to a “one-time” correction maneuver utilized using the Suk technique; 3) short segment fixation using the provisional rods since multiple exchanges prevent long rod utilization; and 4) additional surgical time necessary with multiple removal and insertion of the temporary provisional rods.

Images